In the manufacture of some types of rigid pin-populated printed wiring boards, terminal pins are inserted into apertures formed in the board and electrically engage portions of printed wiring on the boards to provide for connections to electrical circuits. Typically, the spacing between adjacent apertures is extremely small. For example, the spacing between apertures on one board is 0.125 inch. Moreover, each terminal pin typically has a square cross section of, for example, 0.025 inch except in those areas where the pin is formed with lateral ears having a push shoulder and an aperture-engaging portion intermediate the ends thereof.
Due to the close spacing between apertures and the small size of the pin, it is most difficult and tedious to assemble the pins on an individual basis. Additionally, the relatively small size of the pins necessitates delicate handling prior to and during insertion of the pins into the apertures. However, where each board may contain thousands of closely-spaced apertures, efficiency and economy dictate that the pins be prealigned and gang-inserted into the board apertures.
In the past, many techniques have been developed to facilitate the handling of the pins prior to insertion into the board apertures. For example, in one technique, the pins are stamped in a linked configuration having an integrally formed edge-strip carrier. The pins are then fed into an insertion machine in the linked configuration and are separated individually from the carrier. Each of the separated pins is fed individually and independently of the other separated pins through feed chutes and assembled with a supporting structure. In another example, the linked pins are fed to an insertion machine and are separated serially from the carrier. Thereafter, each pin is inserted into the board immediately after being separated from the carrier.
In another techniqe, pins are formed from sheet stock in a parallel array with opposite ends of the terminal pins interconnected by opposed parallel side rails to form a terminal strip. In an assembling operation, one of the side rails is separated from insertion ends of the pins ad the other side rail may be used as a pusher member to insert the separated ends into apertures in a printed wiring board. After the assembling operation, the remaining side rail is separated from the opposite ends of the terminal pins. In an alternate technique, one of the side rails is removed and the pins are assembled with an insertion apparatus. After the assembly with the apparatus, the other side rail is removed from the pins. The insertion of the pins into the board is then accomplished utilizing push shoulders formed on intermediate portions of the pins.
In still another technique, a terminal pin strip includes terminal pins which are interconnected adjacent respective ones of their ends by a removable side rail. Adjacent terminal pins are further interconnected intermediate their ends by a strip member which may be utilized to provide an electrical connection between two or more adjacent terminal pins after the pins have been assembled with a supporting structure. When adjacent terminals are not to be electrically interconnected, the linking strip member must also be severed which is independent of the pins being carried therewith.
Another technique for assembling pins with a substrate is disclosed in U.S. Pat. No. 4,216,580 which issued to W. M. Chisholm on Aug. 12, 1980. As disclosed in U.S. Pat. No. 4,216,580, a plurality of pins are held at opposite ends by carrier strips in an aligned parallel spacing. The pins are positioned adjacent to nests of a stationary jaw of a pin applicator. A movable jaw moves the pins into the nests where an upper carrier strip engages a stripper bar and is separated from the pins. Upon continued motion of the movable jaw, the pins are clamped within the nests between the movable and stationary jaws. The lower strip is then separated from the pins so that the pins are now individually held in by the pin applicator in the aligned parallel spacing. The pin applicator is then moved downwardly to insert the individual pins into apertures of a prepositioned board.